Congenital Heart Defects

Brighter futures for babiesborn with heart defects.

Advances in diagnosis and treatment are giving babies born with congenital heart defects their best odds ever for brighter, healthier futures.

Every parent-to-be wishes for their baby to arrive in good health above all else. A generation ago, fear was a reasonable reaction to the thought that your baby might be born with a congenital heart defect. While heart defects at birth are complex medical conditions, there is good news: Babies born with heart problems today have much healthier future prospects than ever before.

To better understand the nature of congenital heart defects, and for an in-depth look at recent advances in diagnosing and treating them, consulted Dr. Samphant Ponvilawan, a pediatric and adult cardiothoracic surgeon with more than 20 years’ experience healing young hearts.

Eight in a thousand

Heart defects are the most common type of congenital defect; affecting eight of every 1,000 babies. In a typical year in Thailand, about 8,000 babies will be born with a heart defect. “Most types of pediatric heart disease result from congenital heart defects,” says Dr. Samphant. “But in the majority of cases, it’s not possible to identify a precise cause. Some are caused by maternal health conditions including rubella (German measles) and other viral infections. Medication interactions and drug abuse during the first trimester of pregnancy are also known causes.”

Common defects

The term congenital heart defect covers a number of structural abnormalities of the heart’s walls, valves and arteries that are present at birth. The most common defects include:

Atrial Septal Defect (ASD): This condition involves one or more holes in the wall of the heart separating the two upper chambers. The holes allow blood to shift from the left atria to the right. The condition can be detected when a doctor monitors the sounds emitted by the heart and is indicated by specific symptoms such as fatigue.

Ventricular Septal Defect (VSD): VSD is characterized by one or more holes in the heart wall separating the left and right ventricles. The condition allows oxygen-rich blood from the left to mix with oxygen-poor blood from the right. In severe cases, too much blood flows to the lungs and eventually leads to heart failure if left untreated.

Patent Ductus Arteriosus (PDA): This condition occurs when the ductus arteriosus (DA), a vascular connection between the aorta and pulmonary arteries, remains open after the baby’s birth. In healthy hearts, the DA closes within 24 hours after delivery. In babies with PDA, oxygen-rich blood mixes with venous blood and may eventually cause congestive heart failure.

Tetralogy of Fallot (TOF): This is the most common type of congenital cyanosis, which refers to a lack of oxygen in the blood. TOF involves defects of the heart and major blood vessels, including ventricular septal defects (a hole between the left and right ventricles) and the narrowing of the pulmonary artery. The condition impairs blood flow to the lungs and causes low-oxygen blood to leak into the left ventricle before it is pumped into the body’s circulatory system.

Pulmonary Valve Stenosis: This disorder forces the heart to pump harder than normal. It occurs when the pulmonary valve fails to open fully due to stiffness or thickening of pulmonary valve leaflets, or when leaflets fuse together.

Single Ventricle: Single ventricle defects impair the functioning of one lower chamber of the heart. In healthy hearts, the right ventricle pumps venous blood to the lungs while the left ventricle pumps oxygenated blood to the body. In single ventricle hearts, both venous and oxygenated blood are pumped into the same single ventricle; the mixed blood, lacking sufficient oxygen, is pumped into the body’s circulatory system.

Transposition of the Great Arteries (TGA): This congenital disorder involves the complete switching of two major arteries. It results in oxygenated blood going to the lungs while venous blood circulates throughout the body – the opposite of a healthy heart. TGA is a cyanosis condition, i.e. it is marked by insufficient oxygen levels in the bloodstream.

Diagnosing congenital defects

Symptoms are a key element in diagnosing congenital heart problems. “Though very young children aren’t able to describe their own symptoms, diagnosing pediatric heart disease is not very difficult,” says Dr. Samphant. “Doctors simply observe the symptoms which indicate either heart failure or cyanosis (a bluish tinting of the skin). While cyanosis is obvious, pediatric heart failure is not always detected right away as it’s very different from adult heart failure.”

Adult heart failure is indicated by swelling of the face and legs, shortness of breath, and tiring quickly. These are very different from children’s heart failure symptoms. Parents should consult their pediatrician if they notice any of the following symptoms:

Poor growth: Below-normal growth and development indicates some type of medical problem, including the possibility of heart failure. If your child is experiencing poor growth or development, contact your pediatrician;

Frequent resting during feeding: Healthy babies usually drink their milk continuously until full or with only one break to rest. Feedings should always finish in 30 minutes or less. Babies with heart failure take several breaks for rest, and feedings can take over an hour.This is a clear indication of a health problem requiring examination by a pediatrician;

Shortness of breath: This symptom is always serious. Healthy infants take about 40 breaths a minutes; infants with heart failure take about 60 breaths a minute, even when resting.

Better, earlier treatments

Treatments for congenital heart problems have improved greatly in less than a generation. “It’s now possible to treat highly complex heart defects by surgery much earlier than before,” Dr. Samphant explains. “Fifteen years ago, a baby had to grow to 10 kilos or 15 kilos before heart surgery could be considered. With better medical devices, new procedures and advances in technology, doctors can now perform heart surgery whenever a baby needs it.”

Proper post-surgery recovery is critical to ensuring the tiny patient enjoys a healthy future. “Full recoverycan take quite a bit of time,” explains Dr. Samphant. “Complications such as infections, oxygen deficits or low blood pressure do occur in some cases and may affect other organs.”

Dr. Samphant continues: “Today’s generation of medical devices, such as the Extra Corporeal Membrane Oxygenator (ECMO) or heart-lung equipment to support blood circulation, can help save a child’s life at a critical stage of recovery. The ECMO takes over for the heart and lungs until they are strong enough to resume normal function. That’s one of the factors behind the significant drop in post-surgery mortality rates.”

Dr. Samphant is convinced that affected parents have plenty of reason for optimism. “If your baby is diagnosed with a congenital heart defect, you shouldn’t feel dis-heartened,” Dr. Samphant notes. “Nearly every baby – about 99 percent – can be treated successfully. If you learn as much as you can about the condition and work closely with your pediatrician, the experience will be a lot less difficult than you imagined.”